This invention generally relates to the processing or extrusion of virgin polymer materials and recyclable polymeric materials. More particularly, the invention relates to the processing or extrusion of recyclable polymeric materials by incorporating polybutylene polymers having a relatively lower shear viscosity and optionally a filler(s) into a stream of recyclable polymeric materials prior to or during the processing or extrusion process.
It is well known that a variety of recyclable polymeric materials including thermoplastic elastomers have excellent properties, but lack good melt processability. Even among the normally easily processable polymers, higher toughness and good melt strength are attributes of higher molecular weight grades, and as a result, melt processing machine outputs tend to be inversely related to the desirable qualities of toughness needed for durable goods, etc. and melt strength needed for film, thermoforming, blow molding, injection molding, etc.
It is also well known that recyclable polymeric materials are difficult to process. These difficulties include but are not limited their containing a high filler content, their lack of optimal geometries for feeding in melt compounding equipment, a requirement of excessively high melt temperatures for fluxing, a lack of adequate stabilization which in turn leads to degradation during melt processing, and in particular for thermoset materials, they will not process alone using conventional methods.
Because of increasing concerns about and sensitivity to environmental problems, the use of recyclable polymeric materials is encouraged. It is becoming widespread for consumers to use goods such as recycled paper, recycled cans, and recycled plastics. However, the difficulties encountered during the processing of recyclable polymeric materials adversely affect the availability of consumer goods made from these materials.
Attempts to minimize the processing problems of recyclable polymeric materials have been made and are known. For example, it has been suggested that the incorporation of up to 10 wt % of a high melt index polybutylene polymer will be beneficial. Because no completely satisfactory solution to this problem has been discovered, the need for other and/or better solutions continues to exist.